Transmissions having a separate input shaft and a main shaft can often be difficult to shift due to misalignment. If the main shaft is out of alignment with the input shaft, a shift collar has to move the main shaft into alignment with the input shaft such that the main shaft and input shaft are aligned along a common axis. This movement requires an increase in shift effort. Additionally, the main shaft supports a plurality of gears defining a gear plane. The farther forward the gear plane is, the greater the shift effort is to bring the main shaft into alignment with the input shaft.
One solution to decrease shift effort utilizes a steel bushing between the input shaft and the main shaft. The steel bushing is installed within a bore formed within one end of the input shaft. The main shaft includes an extension that is received within the steel bushing. After the extension is inserted within the steel bushing, a small amount of space remains between an inner surface of the steel bushing and an outer surface of the extension. This space causes the main shaft to droop or sag relative to the input shaft, which creates misalignment. As described above, the shift collar must lift the main shaft into alignment with the input shaft, resulting in increased shift effort.
Thus, there is a need for a transmission that includes a centering device for maintaining a centered relationship between a main shaft and an input shaft interface during vehicle operation that overcomes the above-mentioned deficiencies.